Adrenal Dysfunction and Its Connection to Hypothyroidism
Many people who discover they have a sluggish thyroid or hypothyroidism begin thyroid hormone therapy based solely on lab results. While thyroid replacement can be necessary, it’s important not to overlook another key player — the adrenal glands. When the adrenal glands are under chronic stress, they can disrupt thyroid function, leading to persistent fatigue and hormonal imbalance despite treatment.
Understanding the Adrenal–Thyroid Relationship
The adrenal glands, located above the kidneys, produce hormones such as cortisol, which help the body manage stress, regulate metabolism, and maintain blood pressure. During periods of chronic stress, cortisol levels often remain high. In response, the brain may attempt to lower cortisol production to protect the body — but this same mechanism can also suppress thyroid hormone output, leading to symptoms of hypothyroidism.
This means that when someone experiences long-term stress, the adrenal glands and thyroid gland can both become imbalanced. Treating only the thyroid without addressing adrenal health can be misleading and may even worsen symptoms over time, sometimes resulting in the need for higher doses of thyroid medication.
How Adrenal Dysfunction Affects Thyroid Function
The adrenal and thyroid glands communicate through the hypothalamic-pituitary-adrenal-thyroid (HPAT) axis — a complex hormonal feedback system. When stress is prolonged:
Cortisol levels rise, signaling the body to slow metabolism and conserve energy.
Conversion of T4 (inactive thyroid hormone) to T3 (active thyroid hormone) decreases.
Levels of reverse T3 (rT3) may increase, which blocks thyroid receptors and prevents thyroid hormones from working effectively.
Over time, this leads to what is sometimes called functional hypothyroidism, even when standard lab values appear normal.
Shared Symptoms
Because the adrenal and thyroid systems are closely linked, their symptoms often overlap. Common signs of combined dysfunction include:
Persistent fatigue, even after adequate rest
Feeling “wired but tired” or difficulty falling asleep
Sensitivity to stress or anxiety
Weight gain or trouble losing weight
Feeling cold frequently
Brain fog or poor focus
Low blood pressure or dizziness when standing
Cravings for salty or sugary foods
Why a Combined Assessment Matters
In functional and integrative medicine, we understand that treating the thyroid in isolation may not yield full recovery if adrenal health is compromised. A comprehensive evaluation often includes:
Cortisol testing (salivary or urine) to assess adrenal rhythm
Thyroid panel including TSH, free T3, free T4, reverse T3, and thyroid antibodies
Nutrient analysis for selenium, magnesium, B vitamins, and zinc
Assessment of inflammation, gut health, and toxin exposure
By evaluating both systems, clinicians can identify the root cause and tailor a treatment plan that supports the entire hormonal axis rather than focusing on one gland alone.
Steps Toward Restoring Balance
A balanced approach may include:
Managing stress through mindfulness, breathwork, and restorative sleep
Supporting adrenal recovery with adaptogenic herbs like ashwagandha or rhodiola
Ensuring nutrient-rich, whole-food nutrition with stable blood sugar and adequate protein
Targeted thyroid and adrenal support guided by testing and symptoms
Addressing underlying causes such as inflammation, infections, or toxin load
Key Takeaway
The thyroid and adrenal glands work hand in hand. Chronic stress, poor sleep, and unaddressed adrenal fatigue can all interfere with thyroid health. For patients struggling with fatigue, mood changes, or metabolic slowdown despite normal thyroid labs, it’s essential to look deeper. Supporting adrenal health is often the missing link in achieving optimal thyroid function and long-term vitality.